Head

GCC Code Coverage Report

Directory:	./		Exec	Total	Coverage
File:	lib/libpcap/savefile.c	Lines:	54	148	36.5 %
Date:	2017-11-07	Branches:	26	76	34.2 %


/*	$OpenBSD: savefile.c,v 1.16 2015/12/22 19:51:04 mmcc Exp $	*/

/*
 * Copyright (c) 1993, 1994, 1995, 1996, 1997
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that: (1) source code distributions
 * retain the above copyright notice and this paragraph in its entirety, (2)
 * distributions including binary code include the above copyright notice and
 * this paragraph in its entirety in the documentation or other materials
 * provided with the distribution, and (3) all advertising materials mentioning
 * features or use of this software display the following acknowledgement:
 * ``This product includes software developed by the University of California,
 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
 * the University nor the names of its contributors may be used to endorse
 * or promote products derived from this software without specific prior
 * written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 * savefile.c - supports offline use of tcpdump
 *	Extraction/creation by Jeffrey Mogul, DECWRL
 *	Modified by Steve McCanne, LBL.
 *
 * Used to save the received packet headers, after filtering, to
 * a file, and then read them later.
 * The first record in the file contains saved values for the machine
 * dependent values so we can print the dump file on any architecture.
 */

#include <sys/types.h>
#include <sys/time.h>

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#ifdef HAVE_OS_PROTO_H
#include "os-proto.h"
#endif

#include "pcap-int.h"

#define TCPDUMP_MAGIC 0xa1b2c3d4

/*
 * We use the "receiver-makes-right" approach to byte order,
 * because time is at a premium when we are writing the file.
 * In other words, the pcap_file_header and pcap_pkthdr,
 * records are written in host byte order.
 * Note that the packets are always written in network byte order.
 *
 * ntoh[ls] aren't sufficient because we might need to swap on a big-endian
 * machine (if the file was written in little-end order).
 */
#define	SWAPLONG(y) \
((((y)&0xff)<<24) | (((y)&0xff00)<<8) | (((y)&0xff0000)>>8) | (((y)>>24)&0xff))
#define	SWAPSHORT(y) \
	( (((y)&0xff)<<8) | ((u_short)((y)&0xff00)>>8) )

#define SFERR_TRUNC		1
#define SFERR_BADVERSION	2
#define SFERR_BADF		3
#define SFERR_EOF		4 /* not really an error, just a status */

static int
sf_write_header(FILE *fp, int linktype, int thiszone, int snaplen)
{
	struct pcap_file_header hdr;

	hdr.magic = TCPDUMP_MAGIC;
	hdr.version_major = PCAP_VERSION_MAJOR;
	hdr.version_minor = PCAP_VERSION_MINOR;

	hdr.thiszone = thiszone;
	hdr.snaplen = snaplen;
	hdr.sigfigs = 0;
	hdr.linktype = linktype;

	if (fwrite((char *)&hdr, sizeof(hdr), 1, fp) != 1)
		return (-1);

	return (0);
}

static void
swap_hdr(struct pcap_file_header *hp)
{
	hp->version_major = SWAPSHORT(hp->version_major);
	hp->version_minor = SWAPSHORT(hp->version_minor);
	hp->thiszone = SWAPLONG(hp->thiszone);
	hp->sigfigs = SWAPLONG(hp->sigfigs);
	hp->snaplen = SWAPLONG(hp->snaplen);
	hp->linktype = SWAPLONG(hp->linktype);
}

pcap_t *
pcap_open_offline(const char *fname, char *errbuf)
{
	pcap_t *p;
	FILE *fp;

	if (fname[0] == '-' && fname[1] == '\0')
		fp = stdin;
	else {
		fp = fopen(fname, "r");
		if (fp == NULL) {
			snprintf(errbuf, PCAP_ERRBUF_SIZE, "%s: %s", fname,
			    pcap_strerror(errno));
			return (NULL);
		}
	}
	p = pcap_fopen_offline(fp, errbuf);
	if (p == NULL) {
		if (fp != stdin)
			fclose(fp);
	}
	return (p);
}

pcap_t *
pcap_fopen_offline(FILE *fp, char *errbuf)
{
	pcap_t *p;
	struct pcap_file_header hdr;
	int linklen;

	p = calloc(1, sizeof(*p));
	if (p == NULL) {
		strlcpy(errbuf, "out of swap", PCAP_ERRBUF_SIZE);
		return (NULL);
	}

	/*
	 * Set this field so we don't double-close in pcap_close!
	 */
	p->fd = -1;

	if (fread((char *)&hdr, sizeof(hdr), 1, fp) != 1) {
		snprintf(errbuf, PCAP_ERRBUF_SIZE, "fread: %s",
		    pcap_strerror(errno));
		goto bad;
	}
	if (hdr.magic != TCPDUMP_MAGIC) {
		if (SWAPLONG(hdr.magic) != TCPDUMP_MAGIC) {
			snprintf(errbuf, PCAP_ERRBUF_SIZE,
			    "bad dump file format");
			goto bad;
		}
		p->sf.swapped = 1;
		swap_hdr(&hdr);
	}
	if (hdr.version_major < PCAP_VERSION_MAJOR) {
		snprintf(errbuf, PCAP_ERRBUF_SIZE, "archaic file format");
		goto bad;
	}
	p->tzoff = hdr.thiszone;
	p->snapshot = hdr.snaplen;
	p->linktype = hdr.linktype;
	p->sf.rfile = fp;
	p->bufsize = hdr.snaplen;

	/* Align link header as required for proper data alignment */
	/* XXX should handle all types */
	switch (p->linktype) {

	case DLT_EN10MB:
		linklen = 14;
		break;

	case DLT_FDDI:
		linklen = 13 + 8;	/* fddi_header + llc */
		break;

	case DLT_NULL:
	default:
		linklen = 0;
		break;
	}

	if (p->bufsize < 0)
		p->bufsize = BPF_MAXBUFSIZE;
	p->sf.base = malloc(p->bufsize + BPF_ALIGNMENT);
	if (p->sf.base == NULL) {
		strlcpy(errbuf, "out of swap", PCAP_ERRBUF_SIZE);
		goto bad;
	}
	p->buffer = p->sf.base + BPF_ALIGNMENT - (linklen % BPF_ALIGNMENT);
	p->sf.version_major = hdr.version_major;
	p->sf.version_minor = hdr.version_minor;
#ifdef PCAP_FDDIPAD
	/* XXX padding only needed for kernel fcode */
	pcap_fddipad = 0;
#endif

	return (p);
 bad:
	free(p);
	return (NULL);
}

/*
 * Read sf_readfile and return the next packet.  Return the header in hdr
 * and the contents in buf.  Return 0 on success, SFERR_EOF if there were
 * no more packets, and SFERR_TRUNC if a partial packet was encountered.
 */
static int
sf_next_packet(pcap_t *p, struct pcap_pkthdr *hdr, u_char *buf, int buflen)
{
	FILE *fp = p->sf.rfile;

	/* read the stamp */
	if (fread((char *)hdr, sizeof(struct pcap_pkthdr), 1, fp) != 1) {
		/* probably an EOF, though could be a truncated packet */
		return (1);
	}

	if (p->sf.swapped) {
		/* these were written in opposite byte order */
		hdr->caplen = SWAPLONG(hdr->caplen);
		hdr->len = SWAPLONG(hdr->len);
		hdr->ts.tv_sec = SWAPLONG(hdr->ts.tv_sec);
		hdr->ts.tv_usec = SWAPLONG(hdr->ts.tv_usec);
	}
	/*
	 * We interchanged the caplen and len fields at version 2.3,
	 * in order to match the bpf header layout.  But unfortunately
	 * some files were written with version 2.3 in their headers
	 * but without the interchanged fields.
	 */
	if (p->sf.version_minor < 3 ||
	    (p->sf.version_minor == 3 && hdr->caplen > hdr->len)) {
		int t = hdr->caplen;
		hdr->caplen = hdr->len;
		hdr->len = t;
	}

	if (hdr->caplen > buflen) {
		/*
		 * This can happen due to Solaris 2.3 systems tripping
		 * over the BUFMOD problem and not setting the snapshot
		 * correctly in the savefile header.  If the caplen isn't
		 * grossly wrong, try to salvage.
		 */
		static u_char *tp = NULL;
		static int tsize = 0;

		if (hdr->caplen > 65535) {
			snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
			    "bogus savefile header");
			return (-1);
		}

		if (tsize < hdr->caplen) {
			tsize = ((hdr->caplen + 1023) / 1024) * 1024;
			free(tp);
			tp = malloc(tsize);
			if (tp == NULL) {
				tsize = 0;
				snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
				    "BUFMOD hack malloc");
				return (-1);
			}
		}
		if (fread((char *)tp, hdr->caplen, 1, fp) != 1) {
			snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
			    "truncated dump file");
			return (-1);
		}
		/*
		 * We can only keep up to buflen bytes.  Since caplen > buflen
		 * is exactly how we got here, we know we can only keep the
		 * first buflen bytes and must drop the remainder.  Adjust
		 * caplen accordingly, so we don't get confused later as
		 * to how many bytes we have to play with.
		 */
		hdr->caplen = buflen;
		memcpy((char *)buf, (char *)tp, buflen);

	} else {
		/* read the packet itself */

		if (fread((char *)buf, hdr->caplen, 1, fp) != 1) {
			snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
			    "truncated dump file");
			return (-1);
		}
	}
	return (0);
}

/*
 * Print out packets stored in the file initialized by sf_read_init().
 * If cnt > 0, return after 'cnt' packets, otherwise continue until eof.
 */
int
pcap_offline_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
{
	struct bpf_insn *fcode = p->fcode.bf_insns;
	int status = 0;
	int n = 0;

	while (status == 0) {
		struct pcap_pkthdr h;

		status = sf_next_packet(p, &h, p->buffer, p->bufsize);
		if (status) {
			if (status == 1)
				return (0);
			return (status);
		}

		if (fcode == NULL ||
		    bpf_filter(fcode, p->buffer, h.len, h.caplen)) {
			(*callback)(user, &h, p->buffer);
			if (++n >= cnt && cnt > 0)
				break;
		}
	}
	/*XXX this breaks semantics tcpslice expects */
	return (n);
}

/*
 * Output a packet to the initialized dump file.
 */
void
pcap_dump(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
{
	FILE *f;

	f = (FILE *)user;
	/* XXX we should check the return status */
	(void)fwrite((char *)h, sizeof(*h), 1, f);
	(void)fwrite((char *)sp, h->caplen, 1, f);
}

static pcap_dumper_t *
pcap_setup_dump(pcap_t *p, FILE *f, const char *fname)
{
	if (sf_write_header(f, p->linktype, p->tzoff, p->snapshot) == -1) {
		snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "Can't write to %s: %s",
		    fname, pcap_strerror(errno));
		if (f != stdout)
			(void)fclose(f);
		return (NULL);
	}
	return ((pcap_dumper_t *)f);
}

/*
 * Initialize so that sf_write() will output to the file named 'fname'.
 */
pcap_dumper_t *
pcap_dump_open(pcap_t *p, const char *fname)
{
	FILE *f;
	if (fname[0] == '-' && fname[1] == '\0')
		f = stdout;
	else {
		f = fopen(fname, "w");
		if (f == NULL) {
			snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "%s: %s",
			    fname, pcap_strerror(errno));
			return (NULL);
		}
	}
	return (pcap_setup_dump(p, f, fname));
}

/*
 * Initialize so that sf_write() will output to the given stream.
 */
pcap_dumper_t *
pcap_dump_fopen(pcap_t *p, FILE *f)
{
	return (pcap_setup_dump(p, f, "stream"));
}

FILE *
pcap_dump_file(pcap_dumper_t *p)
{
	return ((FILE *)p);
}

long
pcap_dump_ftell(pcap_dumper_t *p)
{
	return (ftell((FILE *)p));
}

int
pcap_dump_flush(pcap_dumper_t *p)
{

	if (fflush((FILE *)p) == EOF)
		return (-1);
	else
		return (0);
}

void
pcap_dump_close(pcap_dumper_t *p)
{

#ifdef notyet
	if (ferror((FILE *)p))
		return-an-error;
	/* XXX should check return from fclose() too */
#endif
	(void)fclose((FILE *)p);
}


Generated by: GCOVR (Version 3.3)

Line	Branch	Exec	Source
1			/* $OpenBSD: savefile.c,v 1.16 2015/12/22 19:51:04 mmcc Exp $ */
2
3			/*
4			* Copyright (c) 1993, 1994, 1995, 1996, 1997
5			* The Regents of the University of California. All rights reserved.
6			*
7			* Redistribution and use in source and binary forms, with or without
8			* modification, are permitted provided that: (1) source code distributions
9			* retain the above copyright notice and this paragraph in its entirety, (2)
10			* distributions including binary code include the above copyright notice and
11			* this paragraph in its entirety in the documentation or other materials
12			* provided with the distribution, and (3) all advertising materials mentioning
13			* features or use of this software display the following acknowledgement:
14			* ``This product includes software developed by the University of California,
15			* Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
16			* the University nor the names of its contributors may be used to endorse
17			* or promote products derived from this software without specific prior
18			* written permission.
19			* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
20			* WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
21			* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
22			*
23			* savefile.c - supports offline use of tcpdump
24			* Extraction/creation by Jeffrey Mogul, DECWRL
25			* Modified by Steve McCanne, LBL.
26			*
27			* Used to save the received packet headers, after filtering, to
28			* a file, and then read them later.
29			* The first record in the file contains saved values for the machine
30			* dependent values so we can print the dump file on any architecture.
31			*/
32
33			#include <sys/types.h>
34			#include <sys/time.h>
35
36			#include <errno.h>
37			#include <stdio.h>
38			#include <stdlib.h>
39			#include <string.h>
40			#include <unistd.h>
41
42			#ifdef HAVE_OS_PROTO_H
43			#include "os-proto.h"
44			#endif
45
46			#include "pcap-int.h"
47
48			#define TCPDUMP_MAGIC 0xa1b2c3d4
49
50			/*
51			* We use the "receiver-makes-right" approach to byte order,
52			* because time is at a premium when we are writing the file.
53			* In other words, the pcap_file_header and pcap_pkthdr,
54			* records are written in host byte order.
55			* Note that the packets are always written in network byte order.
56			*
57			* ntoh[ls] aren't sufficient because we might need to swap on a big-endian
58			* machine (if the file was written in little-end order).
59			*/
60			#define SWAPLONG(y) \
61			((((y)&0xff)<<24) \| (((y)&0xff00)<<8) \| (((y)&0xff0000)>>8) \| (((y)>>24)&0xff))
62			#define SWAPSHORT(y) \
63			( (((y)&0xff)<<8) \| ((u_short)((y)&0xff00)>>8) )
64
65			#define SFERR_TRUNC 1
66			#define SFERR_BADVERSION 2
67			#define SFERR_BADF 3
68			#define SFERR_EOF 4 /* not really an error, just a status */
69
70			static int
71			sf_write_header(FILE *fp, int linktype, int thiszone, int snaplen)
72			{
73			struct pcap_file_header hdr;
74
75			hdr.magic = TCPDUMP_MAGIC;
76			hdr.version_major = PCAP_VERSION_MAJOR;
77			hdr.version_minor = PCAP_VERSION_MINOR;
78
79			hdr.thiszone = thiszone;
80			hdr.snaplen = snaplen;
81			hdr.sigfigs = 0;
82			hdr.linktype = linktype;
83
84			if (fwrite((char *)&hdr, sizeof(hdr), 1, fp) != 1)
85			return (-1);
86
87			return (0);
88			}
89
90			static void
91			swap_hdr(struct pcap_file_header *hp)
92			{
93			hp->version_major = SWAPSHORT(hp->version_major);
94			hp->version_minor = SWAPSHORT(hp->version_minor);
95			hp->thiszone = SWAPLONG(hp->thiszone);
96			hp->sigfigs = SWAPLONG(hp->sigfigs);
97			hp->snaplen = SWAPLONG(hp->snaplen);
98			hp->linktype = SWAPLONG(hp->linktype);
99			}
100
101			pcap_t *
102			pcap_open_offline(const char fname, char errbuf)
103			{
104			pcap_t *p;
105			FILE *fp;
106
107	✗✓✗✗	8	if (fname[0] == '-' && fname[1] == '\0')
108			fp = stdin;
109			else {
110		4	fp = fopen(fname, "r");
111	✗✓	4	if (fp == NULL) {
112			snprintf(errbuf, PCAP_ERRBUF_SIZE, "%s: %s", fname,
113			pcap_strerror(errno));
114			return (NULL);
115			}
116			}
117		4	p = pcap_fopen_offline(fp, errbuf);
118	✗✓	8	if (p == NULL) {
119		4	if (fp != stdin)
120			fclose(fp);
121			}
122		4	return (p);
123		4	}
124
125			pcap_t *
126			pcap_fopen_offline(FILE fp, char errbuf)
127			{
128			pcap_t *p;
129		8	struct pcap_file_header hdr;
130			int linklen;
131
132		4	p = calloc(1, sizeof(*p));
133	✗✓	4	if (p == NULL) {
134			strlcpy(errbuf, "out of swap", PCAP_ERRBUF_SIZE);
135			return (NULL);
136			}
137
138			/*
139			* Set this field so we don't double-close in pcap_close!
140			*/
141		4	p->fd = -1;
142
143	✗✓	4	if (fread((char *)&hdr, sizeof(hdr), 1, fp) != 1) {
144			snprintf(errbuf, PCAP_ERRBUF_SIZE, "fread: %s",
145			pcap_strerror(errno));
146			goto bad;
147			}
148	✗✓	4	if (hdr.magic != TCPDUMP_MAGIC) {
149			if (SWAPLONG(hdr.magic) != TCPDUMP_MAGIC) {
150			snprintf(errbuf, PCAP_ERRBUF_SIZE,
151			"bad dump file format");
152			goto bad;
153			}
154			p->sf.swapped = 1;
155			swap_hdr(&hdr);
156			}
157	✗✓	4	if (hdr.version_major < PCAP_VERSION_MAJOR) {
158			snprintf(errbuf, PCAP_ERRBUF_SIZE, "archaic file format");
159			goto bad;
160			}
161		4	p->tzoff = hdr.thiszone;
162		4	p->snapshot = hdr.snaplen;
163		4	p->linktype = hdr.linktype;
164		4	p->sf.rfile = fp;
165		4	p->bufsize = hdr.snaplen;
166
167			/* Align link header as required for proper data alignment */
168			/* XXX should handle all types */
169	✓✗✗	4	switch (p->linktype) {
170
171			case DLT_EN10MB:
172			linklen = 14;
173		4	break;
174
175			case DLT_FDDI:
176			linklen = 13 + 8; /* fddi_header + llc */
177			break;
178
179			case DLT_NULL:
180			default:
181			linklen = 0;
182			break;
183			}
184
185	✗✓	4	if (p->bufsize < 0)
186			p->bufsize = BPF_MAXBUFSIZE;
187		4	p->sf.base = malloc(p->bufsize + BPF_ALIGNMENT);
188	✗✓	4	if (p->sf.base == NULL) {
189			strlcpy(errbuf, "out of swap", PCAP_ERRBUF_SIZE);
190			goto bad;
191			}
192		4	p->buffer = p->sf.base + BPF_ALIGNMENT - (linklen % BPF_ALIGNMENT);
193		4	p->sf.version_major = hdr.version_major;
194		4	p->sf.version_minor = hdr.version_minor;
195			#ifdef PCAP_FDDIPAD
196			/* XXX padding only needed for kernel fcode */
197			pcap_fddipad = 0;
198			#endif
199
200		4	return (p);
201			bad:
202			free(p);
203			return (NULL);
204		4	}
205
206			/*
207			* Read sf_readfile and return the next packet. Return the header in hdr
208			* and the contents in buf. Return 0 on success, SFERR_EOF if there were
209			* no more packets, and SFERR_TRUNC if a partial packet was encountered.
210			*/
211			static int
212			sf_next_packet(pcap_t p, struct pcap_pkthdr hdr, u_char *buf, int buflen)
213			{
214		76	FILE *fp = p->sf.rfile;
215
216			/* read the stamp */
217	✓✓	38	if (fread((char *)hdr, sizeof(struct pcap_pkthdr), 1, fp) != 1) {
218			/* probably an EOF, though could be a truncated packet */
219		4	return (1);
220			}
221
222	✗✓	34	if (p->sf.swapped) {
223			/* these were written in opposite byte order */
224			hdr->caplen = SWAPLONG(hdr->caplen);
225			hdr->len = SWAPLONG(hdr->len);
226			hdr->ts.tv_sec = SWAPLONG(hdr->ts.tv_sec);
227			hdr->ts.tv_usec = SWAPLONG(hdr->ts.tv_usec);
228			}
229			/*
230			* We interchanged the caplen and len fields at version 2.3,
231			* in order to match the bpf header layout. But unfortunately
232			* some files were written with version 2.3 in their headers
233			* but without the interchanged fields.
234			*/
235	✓✗✗✗	34	if (p->sf.version_minor < 3 \|\|
236	✗✓	34	(p->sf.version_minor == 3 && hdr->caplen > hdr->len)) {
237			int t = hdr->caplen;
238			hdr->caplen = hdr->len;
239			hdr->len = t;
240			}
241
242	✗✓	34	if (hdr->caplen > buflen) {
243			/*
244			* This can happen due to Solaris 2.3 systems tripping
245			* over the BUFMOD problem and not setting the snapshot
246			* correctly in the savefile header. If the caplen isn't
247			* grossly wrong, try to salvage.
248			*/
249			static u_char *tp = NULL;
250			static int tsize = 0;
251
252			if (hdr->caplen > 65535) {
253			snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
254			"bogus savefile header");
255			return (-1);
256			}
257
258			if (tsize < hdr->caplen) {
259			tsize = ((hdr->caplen + 1023) / 1024) * 1024;
260			free(tp);
261			tp = malloc(tsize);
262			if (tp == NULL) {
263			tsize = 0;
264			snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
265			"BUFMOD hack malloc");
266			return (-1);
267			}
268			}
269			if (fread((char *)tp, hdr->caplen, 1, fp) != 1) {
270			snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
271			"truncated dump file");
272			return (-1);
273			}
274			/*
275			* We can only keep up to buflen bytes. Since caplen > buflen
276			* is exactly how we got here, we know we can only keep the
277			* first buflen bytes and must drop the remainder. Adjust
278			* caplen accordingly, so we don't get confused later as
279			* to how many bytes we have to play with.
280			*/
281			hdr->caplen = buflen;
282			memcpy((char )buf, (char )tp, buflen);
283
284			} else {
285			/* read the packet itself */
286
287	✗✓	34	if (fread((char *)buf, hdr->caplen, 1, fp) != 1) {
288			snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
289			"truncated dump file");
290			return (-1);
291			}
292			}
293		34	return (0);
294		38	}
295
296			/*
297			* Print out packets stored in the file initialized by sf_read_init().
298			* If cnt > 0, return after 'cnt' packets, otherwise continue until eof.
299			*/
300			int
301			pcap_offline_read(pcap_t p, int cnt, pcap_handler callback, u_char user)
302			{
303		76	struct bpf_insn *fcode = p->fcode.bf_insns;
304			int status = 0;
305			int n = 0;
306
307	✓✗	76	while (status == 0) {
308		38	struct pcap_pkthdr h;
309
310		38	status = sf_next_packet(p, &h, p->buffer, p->bufsize);
311	✓✓	38	if (status) {
312	✓✗	4	if (status == 1)
313		4	return (0);
314			return (status);
315			}
316
317	✗✓✗✗	34	if (fcode == NULL \|\|
318			bpf_filter(fcode, p->buffer, h.len, h.caplen)) {
319		34	(*callback)(user, &h, p->buffer);
320	✓✗	34	if (++n >= cnt && cnt > 0)
321		34	break;
322			}
323	✓✓✓	106	}
324			/XXX this breaks semantics tcpslice expects /
325		34	return (n);
326		38	}
327
328			/*
329			* Output a packet to the initialized dump file.
330			*/
331			void
332			pcap_dump(u_char user, const struct pcap_pkthdr h, const u_char *sp)
333			{
334			FILE *f;
335
336			f = (FILE *)user;
337			/* XXX we should check the return status */
338			(void)fwrite((char )h, sizeof(h), 1, f);
339			(void)fwrite((char *)sp, h->caplen, 1, f);
340			}
341
342			static pcap_dumper_t *
343			pcap_setup_dump(pcap_t p, FILE f, const char *fname)
344			{
345			if (sf_write_header(f, p->linktype, p->tzoff, p->snapshot) == -1) {
346			snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "Can't write to %s: %s",
347			fname, pcap_strerror(errno));
348			if (f != stdout)
349			(void)fclose(f);
350			return (NULL);
351			}
352			return ((pcap_dumper_t *)f);
353			}
354
355			/*
356			* Initialize so that sf_write() will output to the file named 'fname'.
357			*/
358			pcap_dumper_t *
359			pcap_dump_open(pcap_t p, const char fname)
360			{
361			FILE *f;
362			if (fname[0] == '-' && fname[1] == '\0')
363			f = stdout;
364			else {
365			f = fopen(fname, "w");
366			if (f == NULL) {
367			snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "%s: %s",
368			fname, pcap_strerror(errno));
369			return (NULL);
370			}
371			}
372			return (pcap_setup_dump(p, f, fname));
373			}
374
375			/*
376			* Initialize so that sf_write() will output to the given stream.
377			*/
378			pcap_dumper_t *
379			pcap_dump_fopen(pcap_t p, FILE f)
380			{
381			return (pcap_setup_dump(p, f, "stream"));
382			}
383
384			FILE *
385			pcap_dump_file(pcap_dumper_t *p)
386			{
387			return ((FILE *)p);
388			}
389
390			long
391			pcap_dump_ftell(pcap_dumper_t *p)
392			{
393			return (ftell((FILE *)p));
394			}
395
396			int
397			pcap_dump_flush(pcap_dumper_t *p)
398			{
399
400			if (fflush((FILE *)p) == EOF)
401			return (-1);
402			else
403			return (0);
404			}
405
406			void
407			pcap_dump_close(pcap_dumper_t *p)
408			{
409
410			#ifdef notyet
411			if (ferror((FILE *)p))
412			return-an-error;
413			/* XXX should check return from fclose() too */
414			#endif
415			(void)fclose((FILE *)p);
416			}